276 ORIGIN OF SPECIES 



and tended the larvae, and put all to rights. What can be 

 more extraordinary than these well-ascertained facts? If 

 we had not known of any other slave-making ant, it would 

 have been hopeless to speculate how so wonderful an instinct 

 could have been perfected. 



Another species, Formica sanguinea, was likewise first dis- 

 covered by P. Huber to be a slave-making ant. This species 

 is found in the southern parts of England, and its habits 

 have been attended to by Mr. F. Smith, of the British Mu- 

 seum, to whom I am much indebted for information on this 

 and other subjects. Although fully trusting to the statements 

 of Huber and Mr. Smith, I tried to approach the subject in a 

 sceptical frame of mind, as any one may well be excused for 

 doubting the existence of so extraordinary an instinct as 

 that of making slaves. Hence, I will give the observations 

 which I made in some little detail. I opened fourteen nests 

 of F. sanguinea, and found a few slaves in all. Males and 

 fertile females of the slave species (F. fusca) are found 

 only in their own proper communities, and have never been 

 observed in the nests of F. sanguinea. The slaves are black 

 and not above half the size of their red masters, so that the 

 contrast in their appearance is great. When the nest is 

 slightly disturbed, the slaves occasionally come out, and like 

 their masters are much agitated and defend the nest: when 

 the nest is much disturbed, and the larvse and pupae are ex- 

 posed, the slaves work energetically together with their mas- 

 ters in carrying them away to a place of safety. Hence, it 

 is clear, that the slaves feel quite at home. During the 

 months of June and July, on three successive years, I watched 

 for many hours several nests in Surrey and Sussex, and 

 never saw a slave either leave or enter a nest. As, during 

 these months, the slaves are very few in number, I thought 

 that they might behave differently when more numerous; but 

 Mr. Smith informs me that he has watched the nests at 

 various hours during May, June, and August, both in Surrey 

 and Hampshire, and has never seen the slaves, though pres- 

 ent in large numbers in August, either leave or enter the 

 nest. Hence he considers them as strictly household slaves. 

 The masters, on the other hand, may be constantly seen 

 bringing in materials for the nest, and food of all kinds. 



